The effect isnt a hard once per turn, which means that you can constantly take cards from your opponent until they start with absolutely nothing
Isperia wouldn't have been my first choice for a commander and with only 250 decks on EDHREC, it seems like many players feel the same
Despite having access to cheap removal spells, they also rely on impactful cards like Teferi, Hero of Dominaria as win conditions
(You descend each time a permanent card is put into your graveyard from anywhere.) Uchbenbak, the Great Mistake Three generic, one blue, one black, Legendary Creature - Skeleton Horror - 6/4 - Uncommon Vigilance, menace Descend 8 Four generic, one blue, one black mana: Return Uchbenbak, the Great Mistake from your graveyard to the battlefield with a finality counter on it
You may play that card as long as it remains exiled